Technical Field
The present disclosure relates to photodetectors and light emitting devices (LEDs), and more particularly to extending photodetection in photodetectors to long wavelengths and extending light emission from LEDs to long wavelengths on silicon substrate.
Description of the Related Art
Photodetectors are broadly defined as devices which respond to incident electromagnetic radiation by converting the radiation into electrical energy, thereby enabling measurement of the intensity of the incident radiation. A photodetector typically includes some sort of photoconductive device and external measurement circuitry.
Light emitting diodes can be broadly defined as devices which respond to electrical energy with emission of light. For example, a light-emitting diode (LED) is a two-lead semiconductor light source. It is a p-n junction diode, which emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.